nginx [engine x] is a HTTP and , as well as a written by Igor Sysoev. It has been running for more than five years on many heavily loaded Russian sites including Rambler (RamblerMedia.com). According to Netcraft erved or proxied 4.24% busiest sites in January 2010. Here are some of success stories: FastMail.FM, WordPress.com.

I have tried it and it is a must!